1. Technical Field
The present disclosure relates generally to a surgical portal apparatus employing a system for maintaining a fluid-tight seal across a passageway for surgical instruments. In particular, the disclosure relates to a surgical portal apparatus employing a multiple flapper valve mechanism as part of a seal system.
2. Background of Related Art
Surgical procedures such as laparoscopic, arthroscopic, and endoscopic procedures in general are termed minimally invasive at least in part because the incision required is relatively small, perhaps one inch in length or less. Small incisions are preferred because they are inherently less traumatic to the surrounding body tissue. Also, small incisions subject internal organs to a limited exposure to the contaminants in the outside atmosphere. Thus, small incisions enable shorter hospital stays and faster recoveries with less pain and scarring than is common with the larger incisions required for conventional surgery.
Endoscopic surgery is possible due in part to the availability of instruments designed specifically for this purpose. A cannula, for example, is an elongated tube, typically 5 mm to 13 mm in diameter, which may be configured to have a distal end inserted through the small incision to provide a working conduit to an internal body cavity adjacent an operative site. The body cavity is often inflated with an insufflation gas, carbon dioxide for example, to separate the body wall from vital organs. This provides a space where a surgeon may introduce viewing equipment or maneuver tools into position without damaging surrounding tissue. Various other instruments may then be inserted and withdrawn through the cannula for access to the working space and operative site. In order to fit through a cannula and enable a surgeon to manipulate tissue far removed from the incision, instruments adapted for endoscopic surgery typically include a long and narrow cylindrical shaft. The exact size and shape of the instrument shaft, however, may vary for the many instruments required for a single procedure.
Endoscopic procedures generally require that any instrumentation inserted into the patient's body be sealed, i.e. provisions must be made to ensure insufflation gasses, blood and other fluids do not escape the body through the cannula. Furthermore, a seal acts to prevent contamination of the body cavity by the outside environment. In the absence of such a fluid-tight seal, many of the attendant advantages of minimally invasive surgery are lost.
In a typical procedure, a surgeon may need to install a converter to the cannula to ensure a fluid-tight seal is maintained each time a new instrument having a differing diameter is needed. This process can be cumbersome for the surgeon and increase the time a patient must be subjected to the surgery. Accordingly, a need exists for a cannula seal assembly capable of accommodating variously sized instruments while maintaining a fluid-tight seal across the cannula.